can i expand the ammount of memory on my phone

as u all know i only have 5,5 mb of internal memory on my phone.i was wondering if i could add some more because i really want to listen to my mp3's.if anyone knows anything about this please help.
i also want to ask for help with my video camera.i can memorize only a minute of video in 3pg (large res., sound on) i would like to know if that too can be expanded.
PEOPLE I'M LOSING MY NERVES, PLEASE HELP !!!